Project Summary Pilot Awardee #1: Macedo, Etienne, MD, PhD Title: Tubular Health Characterization in Acute Kidney Injury Despite improvement in AKI classification systems for AKI, timely diagnosis and assessment of AKI severity remains challenging. Renal tubule cells perform many of the essential kidney functions, including reabsorption, electrolyte transport, secretion of endogenous molecules and medications, acid/base balance control, and concentration and dilution of urine. Although well recognized as part of kidney health, these components of tubular function are not systematically captured for overall kidney evaluation in AKI. Recent advances in urinary and serum biomarkers of kidney damage have provided new tools to identify tubular injury that can be mapped to specific sites; however, these injury markers have not been correlated with alterations in tubular function. The combination of tubular function assessment in conjunction with kidney injury, glomerular filtration and permeability markers would provide a more accurate